passing |buffer| by reference in AndroidVideoCapturer::OnIncomingFrame

talk/app/webrtc/androidvideocapturer.cc

Index: talk/app/webrtc/androidvideocapturer.cc
diff --git a/talk/app/webrtc/androidvideocapturer.cc b/talk/app/webrtc/androidvideocapturer.cc
index 2d5a1afea9f66b42781099ea4b4621d4df7fc10d..afcfb5bb7c79c314a3cb1fac36f386e72983e8fc 100644
--- a/talk/app/webrtc/androidvideocapturer.cc
+++ b/talk/app/webrtc/androidvideocapturer.cc
@@ -211,7 +211,7 @@ void AndroidVideoCapturer::OnCapturerStarted(bool success) {
 }
 
 void AndroidVideoCapturer::OnIncomingFrame(
-    rtc::scoped_refptr<webrtc::VideoFrameBuffer> buffer,
+    const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& buffer,
     int rotation,
     int64_t time_stamp) {
   RTC_CHECK(thread_checker_.CalledOnValidThread());